diff --git a/Jakefile.js b/Jakefile.js
index baa72ba9..477df8cf 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -1,5 +1,6 @@
 var build = require('./build/build.js'),
-    lint = require('./build/hint.js');
+    lint = require('./build/hint.js'),
+    UglifyJS = require('uglify-js');
 
 var COPYRIGHT = '/*\n Copyright (c) 2010-2012, CloudMade, Vladimir Agafonkin\n' +
                 ' Leaflet is an open-source JavaScript library for mobile-friendly interactive maps.\n' +
@@ -51,7 +52,7 @@ task('build', ['lint'], function (compsBase32, buildName) {
 
 	var path = pathPart + '.js',
 	    oldCompressed = build.load(path),
-	    newCompressed = COPYRIGHT + build.uglify(content),
+	    newCompressed = COPYRIGHT + UglifyJS.minify(files, {warnings: true}).code,
 	    delta = build.getSizeDelta(newCompressed, oldCompressed);
 
 	console.log('\tCompressed size: ' + newCompressed.length + ' bytes (' + delta + ')');
diff --git a/build/build.js b/build/build.js
index a4da18ae..5e07ea80 100644
--- a/build/build.js
+++ b/build/build.js
@@ -40,14 +40,17 @@ exports.getFiles = function (compsBase32) {
 };
 
 exports.uglify = function (code) {
-	var pro = uglifyjs.uglify;
+	var toplevel = uglifyjs.parse(code);
+	toplevel.figure_out_scope();
 
-	var ast = uglifyjs.parser.parse(code);
-	ast = pro.ast_mangle(ast, {mangle: true});
-	ast = pro.ast_squeeze(ast);
-	ast = pro.ast_squeeze_more(ast);
+	var compressor = uglifyjs.Compressor();
+	var compressed_ast = toplevel.transform(compressor);
 
-	return pro.gen_code(ast) + ';';
+	compressed_ast.figure_out_scope();
+	compressed_ast.compute_char_frequency();
+	compressed_ast.mangle_names();
+
+	return compressed_ast.print_to_string() + ';';
 };
 
 exports.combineFiles = function (files) {
@@ -76,4 +79,4 @@ exports.getSizeDelta = function (newContent, oldContent) {
 	}
 	var delta = newContent.replace(/\r\n?/g, '\n').length - oldContent.replace(/\r\n?/g, '\n').length;
 	return (delta >= 0 ? '+' : '') + delta;
-};
\ No newline at end of file
+};